Three-dimensional measurement device

Abstract

A three-dimensional measurement device which is capable of superimposing and displaying, on a three-dimensional shape, distributions of deviations from a plurality of geometric elements is provided. There are included a deviation calculation unit for determining first deviations from the first geometric element with respect to the first point cloud, and determining second deviations from the second geometric element with respect to the second point cloud. The three-dimensional shape display unit superimposes and displays, on the three-dimensional shape, a distribution of the first deviations from the first geometric element and a distribution of the second deviations from the second geometric element.

What is claimed is: 
     
       1. A three-dimensional measurement device comprising:
 a shape measurement unit configured to measure respective three-dimensional positions of a plurality of measurement points in a three-dimensional space, and to generate a point cloud representing a three-dimensional shape of a measurement target object from the respective three-dimensional positions; 
 a display configured to display the three-dimensional shape of the measurement target object based on the point cloud; 
 a selector configured to receive a position on the three-dimensional shape displayed by the display, and to select, based on the position on the three-dimensional shape, a subset of the point cloud, a first subset of the point cloud selected, based on a first position received as the position by the selector, and a second subset of the point cloud selected, based on a second position received as the position by the selector, the second position being different from the first position; 
 an extractor configured to determine, as a first reference surface, a first geometric element of a basic shape fitting the first subset of the point cloud selected by the selector, and determine, as a second reference surface, a second geometric element of a basic shape fitting the second subset of the point cloud selected by the selector; 
 a calculator configured to determine first deviations of the first subset of the point cloud with respect to the first reference surface along a normal direction of the first reference surface, and second deviations of the second subset of the point cloud with respect to the second reference surface along a normal direction of the first reference surface; and, 
 a display controller configured to control the display to display, on the three-dimensional shape, both a distribution of the first deviations with respect to the first reference surface and a distribution of the second deviations with respect to the second reference surface. 
 
     
     
       2. The three-dimensional measurement device according to  claim 1 , further comprising a region designator configured to designate a first parameter, along the normal direction of the first reference surface, representing a first deviation display target region including the first reference surface,
 wherein the display controller is configured to control the display to display the distribution of the first deviations with respect to the first reference surface within the first deviation display target region designated by the first parameter. 
 
     
     
       3. The three-dimensional measurement device according to  claim 2 , wherein the region designator is configured to further designate a second parameter, along the normal direction of the second reference surface, representing a second deviation display target region including the second reference surface,
 wherein the display controller is configured to control the display to display the distribution of the second deviations with respect to the second reference surface within the second deviation display target region designated by the second parameter. 
 
     
     
       4. The three-dimensional measurement device according to  claim 1 , further comprising a shape type designation unit for receiving designation of a type of the basic shape with respect to the first reference surface,
 wherein the extractor is configured to determine the first reference surface based on the designation of the type of the basic shape with respect to the first reference surface, 
 wherein the basic shape is a plane, a cylinder, a cone, or a sphere, and 
 wherein the calculator unit determines deviations in a normal direction from a surface of the plane, a side surface of the cylinder, a side surface of the cone, or a surface of the sphere. 
 
     
     
       5. The three-dimensional measurement device according to  claim 1 , wherein the display controller is configured to control the display to display the distribution of the first deviations by assigning, to the first subset of the point cloud, different colors according to the first deviations. 
     
     
       6. The three-dimensional measurement device according to  claim 5 , wherein the display controller is configured to control the display to display the distribution of the second deviations by assigning, to the second subset of the point cloud, different colors according to the second deviations. 
     
     
       7. A three-dimensional measurement device comprising:
 a shape measurement unit configured to measure respective three-dimensional positions of a plurality of measurement points in a three-dimensional space, and to generate a point cloud representing a three-dimensional shape of a measurement target object from the respective three-dimensional positions; 
 a display configured to display the three-dimensional shape of the measurement target object based on the point cloud; 
 a type designator configured to receive a type of a basic shape from shapes including a cylinder, a cone, and a sphere; 
 a selector configured to receive a position on the three-dimensional shape displayed by the display, and to select, based on the position on the three-dimensional shape, a subset of the point; 
 an extractor configured to determine, as a curved reference surface, a geometric element of the basic shape fitting a subset of the point cloud selected by the selector, the basic shape corresponding the type of the basic shape designated by the designator; 
 a calculator configured to determine deviations of the subset of the point cloud with respect to the curved reference surface along a normal direction of the curved reference surface; and 
 a display controller configured to control the display to display, on the three-dimensional shape, a distribution of the deviations with respect to the curved reference surface. 
 
     
     
       8. The three-dimensional measurement device according to  claim 7 , further comprising a region designator configured to designate a parameter, along the normal direction of the curved reference surface, representing a deviation display target region including the curved reference surface,
 wherein the display controller is configured to control the display to display the distribution of the deviations with respect to the curved reference surface within the deviation display target region designated by the parameter. 
 
     
     
       9. The three-dimensional measurement device according to  claim 7 ,
 wherein the basic shape is a cylinder, a cone, or a sphere, and 
 wherein the calculator determines deviations in a normal direction from a side surface of the cylinder, a side surface of the cone, or a surface of the sphere. 
 
     
     
       10. The three-dimensional measurement device according to  claim 7 , wherein the display controller is configured to control the display to display the distribution of the deviations by assigning, to the subset of the point cloud, different colors according to the deviations. 
     
     
       11. The three-dimensional measurement device according to  claim 1 , wherein a third subset of the point cloud is selected, based on a third position received as the position by the selector, wherein the extractor is configured to further determine a third geometric element fitting the third subset of the point cloud selected by the selector, and wherein the calculator is configured to further calculate a dimension of the measurement target object based on the third geometric element. 
     
     
       12. The three-dimensional measurement device according to  claim 1 , further comprising:
 a stage having a horizontal surface on which the measurement target object is to be disposed; and 
 a rotation driver configured to rotate the stage with respect to the shape measurement unit around a rotation axis along a vertical direction, 
 wherein the shape measurement unit generates the point cloud representing the three-dimensional shape of the measurement target object by synthesizing pieces of the respective three-dimensional positions measured at different rotation angles around the rotation axis of the stage. 
 
     
     
       13. The three-dimensional measurement device according to  claim 7 , further comprising:
 a stage having a horizontal surface on which the measurement target object is to be disposed; and 
 a rotation driver configured to rotate the stage with respect to the shape measurement unit around a rotation axis along a vertical direction, 
 wherein the shape measurement unit generates the point cloud representing the three-dimensional shape of the measurement target object by synthesizing pieces of the respective three-dimensional positions measured at different rotation angles around the rotation axis of the stage. 
 
     
     
       14. The three-dimensional measurement device according to  claim 4 , wherein the shape type designation unit further receives designation of a type of the basic shape with respect to the second reference surface, the extractor further determines the second reference surface based on the designation of the type of the basic shape with respect to the second reference surface.